Multiple origins of extra electron diffractions in fcc metals

Area of Science:

• Materials Science
• Solid-State Physics
• Electron Microscopy

Background:

• Diffuse intensities in electron diffraction are commonly attributed to chemical short-range order in concentrated alloys.
• Recent studies have questioned the direct link between diffuse intensities and ordering phenomena.

Purpose of the Study:

• To investigate the nonordering origins of diffuse intensities observed in electron diffraction patterns.
• To differentiate between ordering and nonordering contributions to scattering phenomena.

Main Methods:

• Experimental electron microscopy was employed to capture diffraction patterns.
• Multislice diffraction simulations were utilized to model scattering phenomena.
• Analysis focused on identifying contributions from thermal and static displacements.

Main Results:

• Diffuse intensities are largely explained by thermal and static displacement scattering.
• Chemical short-range order is not the primary cause of observed diffuse intensities.
• Planar defects and surface effects may also contribute to scattering patterns.

Conclusions:

• The interpretation of diffuse intensities in electron diffraction needs re-evaluation.
• Nonordering effects, particularly displacements, are significant contributors to observed patterns.
• Further research should consider multiple scattering sources for accurate analysis.